Ostomy patients with flush or recessed stomas have found that if external pressure is applied in the peristomal region, sufficient protrusion of the stoma may occur to aid in the discharge of effluent directly into the collection pouch, thereby prolonging the effectiveness of the adhesive seal between the faceplate and the peristomal skin surfaces. Some manufacturers of ostomy appliances have therefore provided relatively rigid convex annular inserts for use with the coupling rings of adhesive faceplates having skin barrier wafers attached thereto. In theory, such an insert is intended to deform the skin barrier wafer to increase peristomal pressure when the appliance is worn but, in practice, the insert usually lacks sufficient convexity to produce a significant change in the contour of the wafer. Inserts with greater convexity have been unavailable, presumably because of the excessive forces that would seem necessary, and the damage of faceplate coupling ring might sustain, in fitting such an insert into place. Also, to the extent that an insert having a convexity sufficient to depress the peristomal skin surfaces to a substantial extent would also encounter a reactionary force by reason of the resilience of the peristomal area sought to be depressed or deformed, an insert of greater convexity might actually reduce the effectiveness of the adhesive attachment between the faceplate and the skin. Such an effect would be especially noticeable when changing a pouch, since the forces applied to separate a pouch from the faceplate, added to the forces exerted by the skin against the convexity of the faceplace, may be more than enough to cause unintentional separation of the faceplate from the skin.
U.S. Pat. No. 4,834,731 discloses two-piece appliances (FIGS. 7-11) in which the faceplate components are provided with convex pressure rings by the manufacturer or are inserted by the user just prior to adhesive application of such a faceplate to the skin; in either case, such a pressure ring is secured to the proximal or bodyside surface of the faceplate rather than being inserted through the faceplate coupling ring. While such a construction eliminates or reduces the aforementioned risks of coupling ring damage that might be Caused by insert attachment, it still requires stomal protrusion to occur at the time the faceplate is being adhesively applied to the skin surface with the result that the convexity of the pressure ring may make adhesive attachment of the faceplate more difficult. Other references indicating the state of the art are U.S. Pat. Nos. 4,973,323, 4,219,023, 3,385,298 and 2,818,069.
An important aspect of this invention therefore lies in providing a two-piece ostomy appliance in which the faceplate component may be adhesively attached to the peristomal skin surfaces prior to the application of deforming forces produced by a convex pressure ring. Unlike prior systems in which a pressure ring is part of a faceplate component, the system of this invention includes a convex pressure ring as either a permanent or detachable part of the pouch component of the two-piece assembly. Consequently, the forces causing stomal protrusion are not applied until after the faceplate component is already in place, thereby facilitating effective adhesive attachment of the faceplate component to the body. Furthermore, when a pouch is to be changed, there is little risk that the faceplate will also be unintentionally detached from the wearer because, unlike current two-piece systems in which a convex pressure ring is part of a faceplate and reactionary forces by the body against that ring may combine with the applied forces to produce unintentional faceplate removal, the convex pressure ring of this system acts as part of the pouch and, hence, the forces it exerts (and the reactionary forces exerted by the body) are removed (or relieved) along with removal of the pouch.
In a preferred embodiment, the faceplate component is of the "floating flange" type, meaning that the faceplate coupling ring is supported by a flexible web that permits a user to place his/her fingers between the faceplate coupling ring and the remainder of the faceplate at the time the faceplate ring is being joined to the mating ring of a pouch. Under such circumstances, the coupling operation aligns the convex pressure ring with that area of the faceplate against which pressure is to be applied, but substantial pressure causing protrusion of the stoma does not occur until after the components have been coupled together and a belt has been attached to the pouch ring and then tightened about the wearer's body. Subsequent tightening of the belt or strap therefore performs the dual functions of providing additional security to the attachment of the two coupling rings and of urging the convex pressure ring element into forceful contact with an annular portion of the flexible faceplate disposed within the opening of the faceplate ring to produce convex deformation of the faceplate and the desired extent of stomal protrusion.
The extent of stomal protrusion may be varied to some extent by adjusting the tightness of the belt. In addition, or alternatively, the extent of protrusion be varied by selecting a pouch component, or a pressure ring insert for a pouch component, that has the desired degree of convexity. In one embodiment of this invention, the convex pressure ring is a separate element that may be attached to and detached from a pouch coupling ring. Therefore, whether a convex pressure ring is to be used at all, and the selection of a convex pressure ring that produces the desired extent of stomal protrusion, are decisions that the wearer may make at the time the appliance is being applied.
The term "two-piece appliance" is used here in its usual sense to mean an appliance having separate pouch and faceplate components that are joined together at the time of use, in contrast to a one-piece appliance in which the pouch and faceplate are inseparable. Therefore, even though the pressure ring element used as part of this invention may itself be an element that is separable from the pouch coupling ring, and therefore constitutes an additional element, the appliance may still be properly regarded as a two-piece appliance.
Briefly, the appliance comprises a pouch having a pair of side walls, one of which is provided with a stoma-receiving opening and a first coupling ring secured to that wall about the opening. The faceplate is provided with a stoma-receiving aperture and has a bodyside surface provided with adhesive means, preferably in the form of a pliant, adhesive, moisture-absorbing skin barrier material, for adhesive attachment of the faceplate to a patient. The faceplate also includes a pouchside surface with a second coupling ring connected thereto for mating engagement with the first coupling ring of the pouch. The faceplate's second coupling ring extends about the stoma-receiving aperture and has an opening substantially larger than that aperture to expose a flexible and deflectable annular portion of the faceplate within that opening. Pressure ring means are provided by the first coupling ring (i.e., the pouch coupling ring) and is extendable into the opening of the second coupling ring for engaging the annular portion of the faceplate and forcing that portion in a bodyside direction when the rings are coupled together and the faceplate is worn.